It is known conventionally that a rotary electric machine control apparatus detects an abnormality of a rotary electric machine such as an electric motor or the control apparatus itself before starting to control driving of the rotary electric machine.
For example, U.S. Pat. No. 8,248,010 B2 (JP-A-2011-135692) discloses a rotary electric machine control apparatus, which is capable of detecting a short-circuit failure, that is, a short-circuit abnormality, of a switching element in an inverter unit and a short-circuit failure of a pre-driver at the time of initial check operation, which is performed before driving of the rotary electric machine is started. The control object of this rotary electric machine control apparatus is a rotary electric machine having two winding sets. For this reason, two inverter circuits are provided in correspondence to the two winding sets.
A short-circuit abnormality is caused sometimes by a conductive foreign particle, which is affixed between two winding sets or two inverter units. However, it is not possible to accurately detect the short-circuit abnormality by the above-referred rotary electric machine control apparatus. As a result, it is likely to be necessitated sometimes to disable both of the two inverter units even when each of the two inverter units is not abnormal. Since the rotary electric machine control apparatus controls the rotary electric machine as a control target, a driver's steering operation cannot be assisted if the rotary electric machine cannot be driven.